Apparatus for refining used crankcase oil



May 18, 1943 w. D. HARRIS APIfARATUS FOR REFINING USED CRANK CASE OILS Filed May 15, 1942 ATTORNEY Patented May 18, 1943 APPARATUS FOR REFINING USED CRANKCASE OIL William D. Harris, Kansas City, Mo.

Application May 13, 1942, Serial No. 442,754

i Claims.

This invention relates to apparatus for rendering available for further use in engines, crank case oil which has becomecontaminated to an extent which ordinarily would render it a waste product. It has been demonstrated by the present inventor that the valuable lubricating properties of oil are not destroyed after ordinary use in an engine, and in fact it has been proved repeatedly that such used oil displays a greater stability than it possessed when it was newly produced from the refinery. This is explained by the action of the engine in supplementing the original refining process by breaking down the unstable constituents remaining in newly refined oil through the combined eects of heat and mechanical agitation. It'will follow therefore, that if the contaminating constituents of the used oil are removed, the reclaimed oil will be superior in at least some respects to freshly refined oil.

Methods for refining used oil have been proposed previously in the United States Letters Patent of Aycock and Harris No. 1,707,671, granted on April 24, 1929, and Patrick No.'1,750,350, granted on March 11, 1930; and apparatus for carrying out such methods has been described in United States Letters Patent of Harris and Aycock No. 1,707,672, granted on April 2, 1929, and Krieger No. 1,820,871, granted on August 25, 1931. The apparatus of the present invention represents vast improvement over the prior art teachings in reducing the time and expense of operating and in facilitating and cleansing of the apparatus.

In the method employed in the prior art, oil in the still is heated to a relatively high temperature, and when the distillation is complete, this heat is entirely wasted. In accordance with this invention, when the oil is drawn from the still, it is brought into heat exchange relationship with a new batch of oil to be refined, thereby preheating the new batch with a consequent saving of time and expense.

The elements of the present apparatus are interconnected by suitable piping and valves so as to facilitate travel of the oil through the system with a minimum of equipment and handling, and to permit cleansing of the parts by the circulation of fluid from one receptacle to another, merely by the operation of a few valves.

My means of accomplishing the foregoing object may be more readily understood by reference to the accompanying drawing which is hereunto annexed and form a part of this specication.

The single gure is a diagrammatic elevational view partially broken away showing the apparatus of the present invention.

A still l0, supported in a suitable frame l2, comprises an outer shell i4 and an inner shell I6 suitably spaced from the outer one for insulating purposes. The inner shell is constructed to Withstand relatively high internal and external presis covered by a cap 28, having suitable threads 30 for connection with a fitting 32 to which a safety valve 34 and a distillate tube 36 are connected. Through suitable ttings, the opposite end of the distillate pipe is connected to the upper end of a l l condenser coil 38, supported in a condenser tank The lower end of the coil 38 is connected through a pipe t2 and gage glass lli, with a condensate or dilution tank t0.

Cooling water for the condenser is supplied from a suitable source through a valve and pipe 50 to the inlet opening 52 at the lower end of the condenser tank d0, whereupon it passes in countercurrent heat exchange relationship with the coil 33 and emerges through an outlet port 54 to a water pump 56 through a pipe 58. The pump 56 discharges through an outlet 60 to a conveniently located sewer connection. The suction side of the pump 56 is connected through a pipe 62, stop valve 64 and check valve 66 to the upper portion of the dilution tankll so that by proper manipulation of the valves, the dilution vtank and still can be subjected to a partial vacuum.

The dilution tank is supported upon a bracket 68 projecting from the frame l2, Tand may be anchored by means of suitable straps 70. 'I'he still is fastened to the frame 30 in a similar manner by straps l2. The dome of the still is fitted with a plurality of alternate disks 14 and rings 'IB arranged to form a cartridge and depending from the cap Z3. One or more electric heating elements 'i8 are fitted throughthe still wall to serve as the source of heat.- Each element is enclosed within a casing Sli'whi'ch is successively coated with nickel and chromium and highly polished to resist corrosion. and facilitate cleaning. The still is also provided with a clean-out opening 82 which is normally closed by acover 84. Other fittings include a thermometer 85 to indicate still temperatures, a drain cock or air vent 88 in the pipe line i2 between the condenser coil and the dilution tank, a drain cock 90 for the dilution tank itself, a pressure gage 92 in the Water supply-line, and a vacuum gage 94 conthe dilution tank.

The frame |2 is provided with a platform 96 for supporting an open top contact vessel 98 directly below the still. This contact vessel is preferably composed of an inner wall and an outer wall |02 spaced therefrom and filled with suitable heat insulating material |84. The bottom of the contact vessel is provided with an outlet opening |86, which through suitable piping |08 and a stop valve IIB, is connected with the intake side of a pump I2. Another opening H4 is provided near the bottom of the contact vessel, which connects it by a length of pipe I I6 with the lower end of a heat exchange coil II8 supported within a heat exchange and mixing tank |28. The upper end of the heat exchange coil II8 is connected through a nipple |22, valve |24, fourway tting |26 and valve |28 with an opening I 3! formed nearer the top of the contact vessel 98. The lower branch of the four-way fitting |26 is connected through a suitable pipe line |32, a T- fitting |34, and a lfour-Way fitting |36, with the delivery side v'of the pump II2. The pipe line |732 is provided with an intermediate branch pipe |38 which, through a stop valve |40, feeds a retort washer nozzle |42 passing through the cover 84. The upper branch of the four-way fitting |26 is connected with a pipe |44, containing a stop valve |46, terminating in a branched line. One branch is connected through a stop valve |48 with a pipe |50 leading to an opening |52 at the bottoni of the mixing tank |20; the other branch .includes a pipe |54, which is in turn branched to connect with the still inlet opening I8 through a pipe |56 on the one hand, and through a stop valve |58 to a contact vessel feed pipe |60, on the other. An agitator |62 isfsuitably clamped on the wall vof the mixing tank |20, with its shaft |64 carrying blades at its lower end.

A by-pass |64 is 'connected in the line |08 intermediate the contact vessel and the valve H8, which, through a stop valve |66, communicates with the T |34. The pump delivery line is provided with a pressure `gage |68, which may be connected at the `four-way fitting |36. The upper branch of the four-way fitting |36 is connected through ajstop valve |16 with the inlet of a lter press |12. The outlet Vof the press is connected ythrough a stop Valve |14 with a filler pipe |16, and vthrough asto'p valve |18 and pipe line A|80 witha nozzle |82 located above the contact vessel 98.

The used oil to be refined by the present apparatus should'be treated first with sulfuric acid in an open vessel. vParticularly heavy oil may require thinning with kerosene if the best results are-to beachieved. After the used oil has settled, it is agitated during the addition of 66 degree Baume sulfuric acid (commercial 1.835 specific gravity) in approximate proportions of up to one gallon of acid to lfiftygallons of oil. Theaddition of acid and agitation should be continued however until the carbon particles become separated as distinct specks about the size of a pin head or larger and the oil between the particles is in a clear condition. The thus treated oil is then permitted to stand for a period ranging from six -to eighteenhours, during which the acid sludge will settle and the oil will be clear of the carbon particles.

Assuming that all valves and cocks ofV the apparatus 'havebeen closed, the valve 48 will be opened and circulation begun through the condenser tank 40 and pipe 58 to the pump 56 and discharged `through the outlet `6|! to the sewer. The valve 64 is also opened so as toestablishfcom- .asiatica munication between the pump and the dilution tank 46, condenser coil 38 and still I9, thereby reducing the still pressure to a subatmospheri(A value.

The oil to be treated is transferred to the mixing tank |20 preferably, so as to cover the heat exchange coil IIS and the agitator |62 set in operation. To fifty gallons of such oil there is added 2O to 22 pounds of a, sulfuric acid treated clay such as Retrol, a well known product of the Filtrol Corporation. This clay serves to restore the original color to the oil, particularly at elevated temperatures. After these materials have been thoroughly mixed, the bottom of the mixing tank |20 is placed in communication with the still by opening the valve |48, whereupon the vacuum created by the pump 56 will elevate the mixture into the still. The valve |48 will then be closed and current will be supplied to the heating element or elements 78. The mixing tank |20 will then be supplied with a new batch of oil to be treated in accordance with steps to be described subsequently.

As the temperature in the still rises, some water will probably be distilled oif, and by maintaining a relatively slight vacuum, all of the moisture can be removed without experiencing excessive foaming. When the still temperature reaches about 325 F., the degree of Vacuum should be increased gradually by properly manipulating the valves, and if it appears from the gage glass 44 that part of the oil itself is passing to the dilution tank, the cock 88 can be opened to vent the system to an vextent necessary to correct this condition. By careful observaion of the gage glass, it is possible to obtain a maximum degree of vacuum in the system by the time the still temperature reaches about 425 F., depending upon the desired viscosity of the end product. After the necessary heat has been applied, the circuit to the heater is opened, yet the flow of condensing water may be continued for a brief period. However, when all of the distillate to be removed has been condensed, the valve 48 will be closed, whichA will of course, stop the action of the pump 56 At this point, the Valves |24 Aand v|46 between the still inlet and the contact vessel port I4 may be opened for a moment for the purpose of sucking air into the 'still and thereby clearing this pipe line of any obstructions. The vacuum in the system is then broken by opening the vent 88 and at this time, the dilution tank 46 may be drained by opening the cock 98.

The product remaining in the still requires some further treatment with reagents, which is carried out in the contact vessel 98. Into this vessel there is deposited for each fifty gallons of oil being treated, about 8 pounds of a clay of the type of 200 mesh'fullers'earth, one suchproduct being known commercially as Refinolite Compound #1, and about 1A.; pound of an oil insoluble neutralizing agent such as the material sold on the open market as Fl C. D. X.

Then the valves `I46and |24 are opened to permit oil to flow from the s'tillinto the heat exchange coil I8, wherein heat is transferred from the hot oil to the new batch in the mixing tank. The agitator |62 will be set in operation at this time so as to mix the new batch of oil with 20 to 22 lpounds of vthe Retrol clay already referred to, which is described in trade-mark registration No. 304,074 as la chemically treated colloidal clay adapted for use as Ia decolorizing, bleaching, filtering, purifying and "absorbing medium.

The hot oil flowing thrtmgh 4the coil |I8 will pass through the pipe ||6 into the contact vessel 98 where it encounters the treating agents previously placed therein. When all of the oil has owed from the still, which can be determined by the height of oil in the contact vessel 98 or by opening the valve |28, the valves |46 and |24 will be closed and the valve |28 opened. The valve in the suction line |08 is also opened and operation of the pump ||2 is started. Oil is then drawn from the bottom of the vessel 98 through pipe |08, valve ||0, pump ||2, and returned to the contact vessel through pipe |32 and valve |28. When this circulation has been established, valve |40 leading to the still is opened and valve |28 is closed. Then valve |58 is opened so that the hot oil flushing through the still will remove any loose composition which may have settled therein and cause it to ow into the contact vessel. The valve |24 leading to the heat exchange coil ||8 is next opened and the valve |40 closed. The circulation is now from the bottom of the contact vessel, through the pump and coil, and back into the contact vessel When the still has ceased draining through the pipe |60, the valve |58 will be closed.

The water pump 56 is again started by opening the valve 48, and when a suiiicient vacuum has been established, the valve |48 is opened to draw the new batch vof oil from the mixing tank into the still. The agitator |62 will be stopped when the oil level in the tank drops. When all of the oil has been drawn from the tank |20 into the still, the valve |48 is closed and the distillation process will proceed as before. The valve |24 is then closed and the valve |28 opened so that circulation from the contact vessel to the pump and back to the contact vessel will be reestablished, and during all of this time, the distilled oil is being cooled in preparation for its passage through the filter press |12.

The valve |10 leading to the filter press and the valve |18 leading therefrom are next opened so that oil from the bottom of the contact vessel passes through the pump, part of it passing through the filter press, valve |18, pipe |80 and nozzle |82 to the contact vessel, the remainder through the pipe |32 and valve |28 to the contact vessel. Thus it will be seen, that by adjusting the valve |28, the pressure of the oil applied to the filter press can be regulated rather readily. When the ltered oil discharged from the nozzle |82 is sufficiently clear, the valve |18 will be closed and the valve |14 opened, so that the cornpletely refined oil will be delivered through the pipe |16 to suitable containers. In the event of leakage in the press, a pipe line |83 from the bottom of the press to the intake side of the pump is provided, which may be connected through a stop valve |85 for breaking and establishing ow.

The foregoing apparatus illustrates a preferred form of the present invention, but it is to be understood that the various elements described are not to be construed as limitations except where they are set forth in the appended claims.

Having described my invention what I regard as new and desire to secure by Letters Patent is:

1. Apparatus for re-rening used oil comprising the following elements: a still, a contact vessel, a mixing tank, a circulating pump, a pipe connection leading from the mixing tank to the still, a second pipe connection leading from said pump to said first-named pipe connection, a pipe connection normally open to the atmosphere and leading from the contact vessel to said second pipe connection, means to produce a vacuum in the still, heating means within the still Yto volatilize the light ends of the oil in the still, manually operated valves in said second and third pipe connections adapted to be opened when the light ends have been volatilized to permit air to pass therethrough and cleanse said first mentioned pipe connection leading to the still, pipe connections from the bottom of the contact vessel to the pump and from the pump to the still, a valve in said pipe connection leading to the still whereby When said valve is opened the pump will force oil into the still and remove any loose deposit therein.

2. Apparatus for re-rening used oil comprising the following elements: a still, a contact vessel, a mixing tank, a circulating pump, a pipe connection leading from the mixing tank to the still, a second pipe connection leading from said pump to said first-named pipe connection, a pipe connection normally open to the atmosphere and leading from the contact vessel to said second pipe connection, means to produce a vacuum in the-still, heating means within the still to volatilize the light ends of the oil in the still, manually operated valves in said second and third pipe connections adapted to be opened when the light ends have been volatilized to permit air to pass therethrough and cleanse said rst mentioned pipe connection leading to the still, pipe connections to connect said still to a heat exchange coil mounted in said mixing tank, means to connect the other end of said coil to the contact vessel, pipe connections from the bottom of the contact vessel to the pump and from the pump to the still, a valve in said pipe connection leading to the still whereby when said valve is opened the pump will force oil into the still and remove any loose deposit therein.

3. Apparatus for re-refining used oil comprising the following elements: a still, a contact vessel, a mixing tank, a circulating pump, a pipe connection leading from the mixing tank to the still, a second pipe connection leading from said pump t0 said first-named pipe connection, a pipe connection normally open to the atmosphere and leading from the contact vessel to said second pipe connection, means to produce a vacuum in the still, heating means Within the still to volatilize the light ends of the oil in the still, `manually operated valves in said second and third pipe connections adapted to be opened When the light ends have been volatilized to permit air to pass therethrough and cleanse said first mentioned pipe connection leading to the still, pipe connections from the bottom of the contact vessel to the pump and from the pump to the still, said pipe extending into said still and terminating adjacent the bottom thereof, a valve in said pipe connection leading to the still whereby when said valve is opened the pump will force oil into the still and remove any loose deposit therein.

4. Apparatus for re-reflning used oil comprising the following elements: a still, a contact vessel, a mixing tank, a circulating pump, a pipe connection leading from the mixing tank to the still, a second pipe connection leading from said pump to said first-named pipe connection, a pipe connection normally open to the atmosphere and leading from the contact vessel to said second pipe connection, means to produce a vacuum in the still, heating means Within the still to volatilize the light ends of the oil in the still, manually operated valves in said second and third pipe connections adapted to be opened when the light ends have been volatilized to permit air to pass therethrough and cleanse said first mentioned pipe connection leading to the still, pipe connections to connect said still to a heat exchange coil mounted in said mixing tank, means to connect the 4other end of said coil to the Contact vessel, means to connect said pump to the heat exchange coil, pipe connections from the bottom of the contact vessel to the pump `and from the pump to the still, said pipe extending into 'said still and terminating adjacent the bottom thereof, a Valve in said pipe connection leading to the still whereby When said Valve is opened the pump will force oil into the still and remove any loose deposit therein.

WILLIAM D. HARRIS. 

